public class Kwadrat {

        private static int id;
        public int dlugosc;

        public Kwadrat(){
            this.dlugosc = 1;
            System.out.println("Stworzono kwadrat o boku 1.");
        }
        public Kwadrat(int b) throws IllegalArgumentException{
            if(b > 0) {
                this.dlugosc = b;
                System.out.println("Stworzono kwadrat o boku "+ this.getDlugosc() +".");
            }
            else throw new IllegalArgumentException();
        }
        public Kwadrat(Kwadrat k1)
        {
            this.dlugosc = k1.dlugosc;
            System.out.println("Stworzono kwadrat o boku "+ k1.getDlugosc() +".");
        }
        public int getDlugosc(){
            return this.dlugosc;
        }
        public int getId(){
            return this.id;
        }
        public int pole(){
            return (this.dlugosc*this.dlugosc);
        }
        public static class Prostokat extends Kwadrat
        {
            private int szerokosc;

            public Prostokat() {
                this.dlugosc = 1;
                this.szerokosc = 2;
                System.out.println("Stworzono prostokat o bokach "+ this.getDlugosc() +" i " + this.getSzerokosc() +".");
            }
            public Prostokat(int a, int b) throws IllegalArgumentException{
                if(a > 0 && b > 0) {
                    this.dlugosc = a;
                    this.szerokosc = b;
                    System.out.println("Stworzono prostokat o bokach "+ this.getDlugosc() +" i " + this.getSzerokosc() +".");
                }
                else throw new IllegalArgumentException();
            }
            public Prostokat(Prostokat p1) {
                this.dlugosc = p1.dlugosc;
                this.szerokosc = p1.szerokosc;
                System.out.println("Stworzono prostokat o bokach "+ this.getDlugosc() +" i " + this.getSzerokosc() +".");
            }
            public int getSzerokosc() {
                return this.szerokosc;
            }
            public int pole() {
                return (getDlugosc() * getSzerokosc());
            }
        }

}